EXAFS investigation of the active site of iron superoxide dismutase of Escherichia coli and Propionibacterium shermanii

1996 ◽  
Vol 24 (4) ◽  
Author(s):  
C. Scherk ◽  
M. Schmidt ◽  
H.-F. Nolting ◽  
B. Meier ◽  
F. Parak
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Active Site ◽  
Iron Superoxide Dismutase ◽  
Propionibacterium Shermanii

scholarly journals pH-dependent inhibition by azide and fluoride of the iron superoxide dismutase from Propionibacterium shermanii

1998 ◽  
Vol 331 (2) ◽  
pp. 403-407 ◽  
Author(s):  
Beate MEIER ◽  
Christoph SCHERK ◽  
Marius SCHMIDT ◽  
Fritz PARAK
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Low Ph ◽  
Superoxide Dismutases ◽  
Iron Superoxide Dismutase ◽  
Propionibacterium Shermanii ◽  
Hydroxyl Anion ◽  
Dependent Inhibition ◽  
Ph Dependent ◽  
A Minor

The iron-containing superoxide dismutase from Propionibacterium shermanii shows, in contrast with other iron superoxide dismutases, only a minor inhibition by azide or fluoride (10–100 mM) of up to 23% at pH 7.8. The activity of the protein with Mn bound to the active site was not diminished under the same conditions. The binding constant between azide and the Fe3+ ion was determined as approx. 2 mM and for fluoride approx. 2.3 mM; they are so far comparable to those known for other iron superoxide dismutases. This seems to be a discrepancy because all other iron superoxide dismutases so far known are described as being inhibited by 50–70% by 10 mM azide. However, towards lower pH there was a drastically increased inhibition by both anions. At pH 6.8 about 80% inhibition was exhibited by azide or fluoride at a concentration of 10 mM or higher. In contrast, on increasing the pH, azide or fluoride still bound to the Fe3+ at the active site but their inhibition capacity decreased. This observation implies that both anions bind to the metal at a position that is empty at low pH, whereas at higher pH water or a negatively charged hydroxyl anion is bound. It is likely that the superoxide anion binds to the same position and has to replace the sixth ligand, leading to a diminished catalytic activity of the superoxide dismutase owing to steric and/or electrostatic inhibition of the ligand.

Catalytic role of iron-superoxide dismutase in hydrogen abstraction by super oxide radical anion from ascorbic acid

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86650-86662 ◽  
Author(s):  
Manish K. Tiwari ◽  
Phool C. Mishra
Keyword(s):  
Ascorbic Acid ◽  
Superoxide Dismutase ◽  
Active Site ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Hydrogen Abstraction ◽  
Iron Superoxide Dismutase ◽  
Superoxide Radical Anion ◽  
Catalytic Role

The catalytic role of iron-superoxide dismutase (Fe-SOD) in the working of ascorbic acid (AA) as a superoxide radical anion scavenger has been studied by employing a model developed recently for the active site of the enzyme.

scholarly journals Characterization of iron superoxide dismutase cDNAs from plants obtained by genetic complementation in Escherichia coli.

1990 ◽  
Vol 87 (24) ◽  
pp. 9903-9907 ◽  
Author(s):  
W. Van Camp ◽  
C. Bowler ◽  
R. Villarroel ◽  
E. W. Tsang ◽  
M. Van Montagu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Genetic Complementation ◽  
Iron Superoxide Dismutase

One- and two-dimensional proton NMR studies of the active site of iron(II) superoxide dismutase from Escherichia coli

1994 ◽  
Vol 33 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Li June Ming ◽  
John B. Lynch ◽  
Richard C. Holz ◽  
Lawrence Que
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Active Site ◽  
Proton Nmr ◽  
Two Dimensional ◽  
Nmr Studies
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